* Fixed a bug that prevented thumbnails from loading on certain circumstances (Ex: scrolling too fast on a slow connection).

* Fixed a bug where the thumbnails on playlists would play whenever you hovered over the titles.
* Added a whole new options section on the "Extensions" screen, with the following options:
- Starttime: you can set when the thumbnail will start: (00_00, half or "smart start").
- Loop: activated by default, makes your thumbnail videos loop endlessly.
- Volume: allows you to set the sound volume of the thumbs.

Added brightness effect on thumbnails on hover, fixed some performance issues.